1. Field of the Invention
This invention relates to a tensioner for an endless power transmission belt or the like as well as to a method of making such a tensioner.
2. Prior Art Statement
It is known in the art to provide a tensioner for a power transmission belt that is adapted to be operated in an endless path, the tensioner comprising a support means for being fixed relative to the belt, a belt engaging means carried by the support means and being movable relative thereto, and mechanical spring means operatively associated with the support means and the belt engaging means for urging the belt engaging means relative to the support means and against the belt with a force to tension the belt.
Examples of tensioners of the above mentioned type are provided in the following five U.S. Patents:
(1) U.S. Pat. No. 3,413,866--Ford PA0 (2) U.S. Pat. No. 4,108,013--Sragal PA0 (3) U.S. Pat. No. 4,145,934--Sragal PA0 (4) U.S. Pat. No. 4,151,756--Binder et al PA0 (5) U.S. Pat. No. 4,249,425--Watson PA0 (6) U.S. Pat. No. 3,142,193--Polko PA0 (7) U.S. Pat. No. 4,276,038--Kraft
It appears from item (1) above that a tension spring urges an idler pulley in tensioning engagement against a belt.
It appears from item (2) above that a compression spring urges an idler pulley in tensioning engagement against a belt.
It appears from item (3) above that a leaf spring urges an idler pulley in tensioning engagement against a belt.
It appears from item (4) above that a plurality of bi-metal dish-shaped springs disposed in various stacked relations thereof urge an idler pulley in tensioning engagement against a belt.
It appears from item (5) above that pneumatic means is adapted to threadedly adjust an idler pulley rod of a belt tensioner wherein a pair of dish-shaped springs urge the idler pulley in tensioning engagement against a belt.
It is also known in the art to provide a piston and cylinder arrangement for hydraulically urging an idler pulley in tensioning engagement against a belt.
For example, see the following two U.S. Patents:
It is also known to provide a belt tensioner where friction surface dampening means of the solid type are utilized to tend to dampen vibrations and the like that are imposed on the belt tensioner.